Application of frequency domain deconvolution to DQF-COSY spectra for the determination of coupling constants as a tool for signal assignment based on coupling networks

Scalar coupling constants can be extracted from the cross peaks of correlat ion spectra by applying deconvolution to the frequency domain. This require s high resolution in the directly detected dimension. A three-step automate d procedure is presented as a free package running in combination with a ma jor commercial processing software. The initial step allows one to measure coupling constants in an interactive manner in high-resolution cross-peak m ultiplets of weakly coupled spin systems. The user can follow the recursive analysis to assess the reliability of the results. If needed, the course o f the automatic procedure can be changed. A second module compiles the data of the cross-peak analysis and assembles the proton spin network. The algo rithm assigns data to a given nucleus if it encounters full consistency of both chemical shifts and coupling constants in all relevant cross peaks. Th e pairing of signals symmetric with respect to the diagonal defines the con nectivity of the spin network. The last module displays the coupling networ k in a pleasing presentation. Application to androst-4-ene-3, 17-dione is p resented. This example shows that assignment of the coupling network to the molecular structure becomes straightforward. Copyright (C) 2000 John Wiley & Sons, Ltd.